Install two commercial certificates

I have a trade certificate installed on my server that corresponds to the Webmail (http://www.webmail.mydomain.edu).
I need to install a new certificate for the MTA (mail.mydomain.edu) for the emails used via Microsoft Outlook.

Apparently the bug has been marked to be visible to a restricted group. Not sure why.

In any case I can't help beyond noting that bug 8128's Target Milestone has moved several times and according to pm.zimbra.com, it doesn't seem to be on the "to do" list of any current or near-future Zimbra release, including 7.0.

Its probably private because they are working on it internally. Its a good thing. If you dig around on the forums you may be able to find a few tips on setting up a frontend nginx proxy to have multiple ssl certs.